product backlogs items VS sprint backlog items

Last post 04:16 pm May 14, 2018
by Ian Mitchell
8 replies
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12:00 am June 3, 2014

Hi evey one, i have discussed with my SM about pbi and spbi but i don't understand very well about if a product backlog item is bigger than a sprint backlog item, i said yes because during refining you can split a pbi into a lot of pbis and then you can use during sprint plannning,and then in sprint backlog i would like to know about your experience, what do you think???

03:23 am June 3, 2014

You are right, usually pbis are split and get smaller over time before they reach the sprint backlog, so generally speaking sprint backlog items are smaller than product backlog items.
However, I have also made the experience that during backlog refinement we have split a story in two, and in sprint planning the dev team fastened them together again with a stapler.
You never know.

04:55 am June 3, 2014

A Sprint Backlog Item can be seen as a Product Backlog Item plus a plan for implementing it. In that sense it is additive to, and thus "larger" than, the selected PBI.

The truth is that the two backlogs serve different purposes, and the items within are not directly comparable.

10:02 am December 7, 2014

I really don't understand that question ... What is the "item size" ?

10:23 am January 15, 2015

Each PBI has to be estimated by the dev team. Item size refers to that estimate.

09:49 pm January 15, 2015

I have simple example 3 top PBIs is A,B,C now. In refinement meeting we split A, B into A1, A2, B1, B2, B3 and see that we can only pick A1, A2, B1, B2 for next sprint. At that time all A1, A2, B1, B2, B3, C,....is PBIs but in next sprint A1, A2, B1, B2 will become SPBIs. So you can consider SPBI small as PBI (if compare with B3) or smaller PBI (if compare with C).

Anyway I think item size in this question should be understand by relative way (e.g. Item type) and should not by absolute estimation (in hours) because every item always take different time to finished it.

Thanks,

05:41 am January 19, 2015

The Scrum Guide says at page 12 & 14:

The Product Backlog is an ordered list of everything that might be needed in the product and is the single source of requirements.

The Sprint Backlog is a forecast (…) what functionality will be in the next Increment and the work needed to deliver that functionality. The Sprint Backlog makes visible all of the work (…) The Sprint Backlog is a plan (…)

End quotes.

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So, the Product Backlog and the Sprint Backlog are defined, but an exact definition of PBI’s and SPI’s are not given.

However it is commonly accepted that a PB can contain User Stories and SP contains tasks.

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So for example a User Story can say: “As a telesell company manager, I want the customer to be able to change it’s preferences by himself, in order to reduce my operational costs.”

This requirement can lead to multiple demanding tasks like: setting up a database, defining a user interface, providing for a secure communication channel, etc.

In this example, the User Story could be written down in 5 minutes, where the tasks may take a complete sprint. In this regard, the tasks are much bigger than the requirement.

However, from the business point of view, the individual tasks and results have no individual value. So the requirement of the User Story is much bigger.

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Hmmm, only now I see the original post was not recent. I submit this answer anyway for anyone that is interested.

11:37 pm May 11, 2018
Dear Ian, based on your explanation, the following answer in the Mgmt Plaza practice exam is incorrect, right?
1. Question

Items in the Product Backlog are usually larger than items in the Sprint Backlogs.

  •  True

This is how it works:

  1. Items of different sizes are added to the Product Backlog.
  2. Items are sorted based on their business value.
  3. Then we check the items on the top of the Product Backlog, and if they are large, we’ll break them down into smaller items. We leave the large items on the bottom of the Product Backlog as they are for now.
  4. The business values will be estimated again, and the Product Backlog sorted based on them.

Based on this explanation, the items on the top of the Product Backlog would be, statistically speaking, smaller than the average. Since the items in the Sprint Backlog come from the top of the Product Backlog, we can say that “the items in the Sprint Backlog are usually smaller than the average item in the Product Backlog”.

Remember that we sort the Product Backlog items based only on their business value. The difference in size happens naturally, and is not a basis for sorting.

04:16 pm May 14, 2018

In my view the correct answer would default to false, given that the means of comparison is not elucidated. Refinement can indeed usually be expected to reduce items in their estimated size, but more detail will usually be added. Sprint Planning will add even more detail in terms of a plan for implementation.